Not all accelerators, incubators, and co-working dens are created equal. Depending on who you ask, there can be debate on the similarities and differences between all three. The latest comes from Jason Johnson, one of the founders of the Founder Den, a co-working space in San Francisco. To quote Jason:

"Most co-working spaces lack a curation process which we saw as important
to creating a dynamic, iron-sharpens-iron community, similar to the
traditional private clubs which appealed to the entrepreneurs of prior
innovation eras (steel, railroad, oil, etc.). In New York, SoHo House
and The Core (while less of a co-working space and more of a lounge)
appeal to entrepreneurs. With Founders Den, we sought a unique,
differentiated model of one-half private club and one-half co-working
space."